A man who buried a small boy alive in a coal mine has been executed in China as part of a crackdown on crimes against children.

Four others were also put to death for offences against minors as the country celebrated Children's Day.

They included a man who broke into a primary school and raped 10 girls and three others involved in human trafficking.

China has launched a nationwide campaign against the abduction and selling of women and children, which has become increasingly common in recent years.

The China Daily recently reported that over 10,000 kidnap victims were rescued by police in April alone.

China is marking Children's Day

Girls are sold as brides to poor farmers and boys to families wanting a son.

The Supreme Court's vice president, Shen Deyong, said China was determined to clamp down on crimes against minors as he announced the executions.

"In order to provide a good legal environment for the healthy upbringing of our children, the People's Court has a sacred responsibility," he added.

The five were executed on Tuesday on the eve of Children's Day.

Rape

State media said those put to death included Bu Xiaogang, who kidnapped a 5-year-old boy in central Shaanxi province in July, demanded a 500,000 yuan ($60,000) ransom and then buried him in a coal mine to cover up his crime.

A 28-year-old villager from neighbouring Shanxi province, Du Honghong, was executed for twice breaking into a primary school dormitory and raping 10 girls, the Xinhua News Agency said.

There is a shortage of girls in rural China

Three traffickers were also put to death for smuggling a total of 27 children in Guizhou and Jiangxi provinces.

Crackdown

Mr Shen said the courts had tried 6,400 cases of kidnapping, 600 of human trafficking, 66,000 of rape and 2,500 of child abuse in the last eight years.

The trials resulted in the conviction of more than 145,000 people, with 91,000 sentenced to between five years and the death penalty.

"The heavy penalties in these cases amply fulfils the determination of the court to crack down on this type of crime," Mr Shen said.

According to recent statistics, 7,600 women and 1,814 children were kidnapped and sold in China last year alone.

But police officials say the current two-month police crackdown on trafficking is likely to reveal a huge increase in abductions compared to last year.